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• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C255/00—Carboxylic acid nitriles
  • C07C255/49—Carboxylic acid nitriles having cyano groups bound to carbon atoms of six-membered aromatic rings of a carbon skeleton
  • C07C255/50—Carboxylic acid nitriles having cyano groups bound to carbon atoms of six-membered aromatic rings of a carbon skeleton to carbon atoms of non-condensed six-membered aromatic rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C13/00—Cyclic hydrocarbons containing rings other than, or in addition to, six-membered aromatic rings
  • C07C13/28—Polycyclic hydrocarbons or acyclic hydrocarbon derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C25/00—Compounds containing at least one halogen atom bound to a six-membered aromatic ring
  • C07C25/18—Polycyclic aromatic halogenated hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/06—Non-steroidal liquid crystal compounds
  • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
  • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
  • C09K19/3098—Unsaturated non-aromatic rings, e.g. cyclohexene rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2601/00—Systems containing only non-condensed rings
  • C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
  • C07C2601/16—Systems containing only non-condensed rings with a six-membered ring the ring being unsaturated

Definitions

• the present invention relates to novel cyclohexylcyclohexene derivatives that are useful as electrooptic display materials.
• liquid-crystal display cells include the dynamic scattering mode cell proposed by G.H. Heilmeier et al. in Appl. Phys. Letters, 13 , 46 (1968), the field-effect mode cell proposed by M. Schadt et al. in Appl. Phys. Letters, 18 , 127 (1971), and the quest-host mode cell proposed by G.H. Heilmeier et al. in Appl. Phys. Letters, 13 , 91 (1968).
• liquid-crystal materials used in these liquid-crystal display cells While various characteristics are required of liquid-crystal materials used in these liquid-crystal display cells, the most important one which must be shared by all display cells is that they have a nematic phase over a broad range of temperatures including room temperature. Many of the practically feasible liquid-­crystal materials satisfying this requirement are usually prepared by mixing several or more components including a compound having a nematic phase at a temperature in the vicinity of room temperature and a compound having the nematic phase in the temperature range higher than room temperature. Many of such mixed liquid crystals commercially used today are at least required to have a nematic phase over the entire range of temperatures from -30°C to +65°C.
• An object, therefore, of the present invention is to provide a novel liquid-crystal compound that has a high N-I point and a low C-N or S-N point.
• the compound of formula (I) of the present invention can be produced by one of the following methods: (in the reaction scheme described above, R, n and Y have the same meanings as defined for formula (I); and Z is a fluorine atom, a chlorine atom, a straight-chained alkyl or alkoxyl group having 1 - 9 carbon atoms). (in the reaction scheme described above, R, n and Y have the same meanings as defined for formula (I); and Z is a fluorine atom, a chlorine atom, a straight-chained alkyl or alkoxyl group having 1 - 9 carbon atoms).
• a compound of formula (II) is reacted with a magnesium power in an ether-based solvent such as anhydrous tetrahydrofuran (hereinafter abbreviated as THF) at 15 - 30°C for 1 - 2 hr to prepare a compound of formula (III).
• THF anhydrous tetrahydrofuran
• a solution of a compound of formula (IV) in anhydrous THF is added at 5 - 20°C and the mixture is subjected to reaction at 10 - 30°C for 30 min to 1 hr; thereafter, the reaction product is decomposed with a saturated aqueous solution of ammonium chloride to prepare a compound of formula (V).
• the compound of formula (V) is subjected to reaction in a water-insoluble inert solvent such as toluene for 0.1 - 8 hr under reflux in the presence of an acidic catalyst such as p-toluenesulfonic acid; after cooling the reaction mixture, the solvent layer is washed first with a saturated aqueous solution of sodium hydrogen carbonate, then with a saturated aqueous solution of sodium chloride; after drying, the solvent is distilled off and the crude reaction product is recrystallized from an alcoholic solvent such as ethanol to prepare a compound of formula (VI).
• a water-insoluble inert solvent such as toluene for 0.1 - 8 hr under reflux in the presence of an acidic catalyst such as p-toluenesulfonic acid
• the compound of formula (VI) is dissolved in a water-insoluble inert solvent and catalytically reduced at 20 - 80°C for 6 - 30 hr at a hydrogen pressure of no more than 3 kg/cm2 in the presence of a hydrogenation catalyst such as platinum oxide or Raney nickel to prepare a compound of formula (VII).
• a hydrogenation catalyst such as platinum oxide or Raney nickel
• the compound of formula (VII) is dissolved in an inert solvent such as toluene and reacted with an acidic aqueous solution such as dilute sulfuric acid for 5 - 6 hr under reflux; after cooling the reaction mixture, the solvent layer is washed with water, dried and freed of the solvent by distillation; the crude reaction product is purified by column chromatography on silica gel and further purified by recrystallization from a mixed solvent of n-hexane and toluene to prepare a compound of formula (VIII).
• an inert solvent such as toluene
• an acidic aqueous solution such as dilute sulfuric acid for 5 - 6 hr under reflux
• a compound of formula (IX) is converted to a lithium salt by reaction with lithium in an ether-based solvent such as anhydrous diethyl ether under reflux for 2 - 9 h; to the lithium salt, a solution of the compound of formula (VIII) in an ether-based solvent such as anhydrous diethyl either is added at -20°C to +5°C and reaction is performed at 5 - 25°C for 30 min; the reaction mixture is decomposed with water and the reaction product is extracted with toluene; the extract is washed with water, dried and freed of the solvent by distillation to prepare a compound of formula (X).
• an ether-based solvent such as anhydrous diethyl ether under reflux for 2 - 9 h
• a solution of the compound of formula (VIII) in an ether-based solvent such as anhydrous diethyl either is added at -20°C to +5°C and reaction is performed at 5 - 25°C for 30 min; the reaction mixture is decomposed with water
• the compound of formula (X) is dissolved in n-hexane or toluene; the solution is added to an acetonitrile solution of iodo-trimethylsilane prepared from chlorotrimethylsilane and sodium iodide in acetonitrile and the mixture is subjected to reaction at 5 - 10°C for 30 min - 1 h; in this way, a reaction mixture composed of compounds of formulas (XIV-a), (XIV-b), (XV-a) and (XV-b) is prepared from the compound of formula (X) via an intermediate composed of compounds of formulas (XII), (XIII-a) and (XIII-b).
• a base such as 1,8-­diaza-bicyclo(5,4,0)undecene-7 (hereinafter abbreviated as DBU) is added and reaction is performed at 5 - 30°C for 5 - 20 hr so as to prepare compounds of formulas (XIV-a) and (XIV-b) from compounds of formulas IXV-a) and (XV-b), respectively.
• DBU 1,8-­diaza-bicyclo(5,4,0)undecene-7
• the compounds of formulas (XIV-a) and (XIV-b) are extracted with toluene and the extracts are washed successively with dilute HCl, a saturated acidic aqueous solution of sodium hydrogen sulfite, a saturated aqueous solution of sodium hydrogencarbonate and a saturated aqueous solution of sodium chloride; after drying, the solvent is distilled off from the extracts.
• the mixture of compounds of formulas (XIV-a) and (XIV-b) is dissolved in an inert solvent such as toluene and subjected to reaction under reflux for 1 - 8 hr in the presence of an acidic catalyst such as p-toluenesulfonic acid, thereby isomerizing the cyclohexane ring from a cis- to trans-configuration; in this way, a mixture of compounds of formulas (I-a) and (I-b) or a mixture of compounds of formulas (I-e) and (I-f), all being within the scope of the present invention, is produced in high yield.
• an inert solvent such as toluene
• an acidic catalyst such as p-toluenesulfonic acid
• a mixture of compounds of formulas (I-a) and (I-b) wherein Z is chlorine is dissolved in an aprotic polar solvent such as N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) and reacted with copper cyanide (CuCN) at 190 - 200°C for 8 - 12 hr.
• NMP N-methyl-2-pyrrolidone
• CuCN copper cyanide
• the reaction mixture is added to 30% aqueous ammonia and the reaction product is extracted with toluene.
• the extract is washed successively with 30% aqueous ammonia, water, dilute HCl, a saturated aqueous solution of sodium hydrogen-carbonate and a saturated aqueous solution of sodium chloride. After drying, toluene is distilled off from the extract.
• the crude reaction product is purified by column chromatography on silica gel and further purified by recrystallization from ethanol to prepare a mixture of compounds of formulas (I-c) and (I-d).
• the compounds of formulas (I-c) and (I-d) are isolated from the mixture and recrystallized from ethanol to produce pure compounds of formulas (I-c) and (I-d) within the scope of the present invention.
• the compound of formula (I) of the present invention is a nematic liquid-crystal compound having a very weak positive, a positive or a weak negative anisotropy in dielectric constant. Therefore, when mixed with another nematic liquid-crystal compound having a negative or weak positive anisotropy in dielectric constant, the compound of the present invention can be used as the constituent material of a dynamic scattering mode display cell. Alternatively, it may be used as the constituent material of a field-effect mode display cell when mixed with another nematic liquid-crystal compound having a strong positive anisotropy in dielectric constant.
• Preferred examples of such compounds that can be used in admixture with the compound of formula (I) are listed below: 4′-substituted phenyl 4-substituted benzoate ester, 4′-substituted phenyl 4-substituted cyclohexanecarboxyate ester, 4′-substituted biphenyl 4-­substituted cyclohexanecarboxyate ester, 4′-substituted phenyl 4-(4-substituted cyclohexanecarbonyloxy)benzoate ester, acid 4′-substituted phenyl 4-(4-substituted cyclohexyl)benzoate ester, 4′-substituted cyclohexyl 4-(4-­substituted cyclohexyl)-benxoate ester, 4-substituted 4′-­substituted biphenyl, 4-
• the compound of formula (I) of the present invention has a sufficiently high N-I point to be useful in the preparation of mixed liquid crystals that can be driven at high temperatures; the temperature range in which the compound of formula (I) exhibits a nematic phase than that of known compounds having a similar structure; and the compound of formula (I) has a C-N or S-N point that is much lower than those of known compounds having similar structures.
• Table 3 shows the N-I points of two mixed liquid crystals (B) and (C) containing 90 wt% of mixed liquid crystal (A) which is commercially used today as the host liquid crystal of nematic liquid-crystal materials; liquid crystal (B) additionally contains compound Nos. 8 and 9 of formula (I) (see Table 1) in respective amounts of 5 wt%, and liquid crystal (C) additionally contains compound Nos. 10 and 11 of formula (I) (also see Table 1) in respective amounts of 5 wt%.
• the N-I point of mixed liquid crystal (A) is also shown in Table 3.
• This liquid crystal (A) consists of the following components: Table 3 Mixed liquid crystal N-I point (°C) (A) 54.0 (B) 75.5 (C) 70.0
• This compound (20.0 g, 0.0678 mol) was dissolved in toluene (50 ml). A catalytic amount of platinum oxide was added to the solution, which was stirred at ambient temperature and atmospheric pressure to perform a hydrogenation reaction. After completion of the reaction, the reaction mixture was filtered to remove the catalyst. By distilling off toluene from the filtrate, a crude product containing a compound having the structure shown below was obtained in an amount of 19.3 g:
• the extract was successively washed with dilute HCl, a saturated acidic aqueous solution of sodium sulfite, a saturated aqueous solution of sodium hydrogen-carbonate and a saturated aqueous solution of sodium chloride, and subsequently dried. By distilling off the solvent, a crude reaction product was obtained.
• This crude reaction product was dissolved in toluene (6 ml) and p-toluenesulfonic acid monhydrate (0.033 g, 0.00017 mol) was added to the solution, followed by stirring to effect isomerization under reflux for 3 h. After cooling the reaction mixture, the toluene layer was successively washed with a saturated aqueous solution of sodium hydrogencarbonate and a saturated aqueous solution of sodium chloride, and subsequently dried. By distilling off toluene, a crude reaction product was obtained. This crude reaction product was purified by recrystallization from ethanol containing a small amount of n-hexane. As a result, a mixture of two compounds having the structures shown below was obtained in an amount of 1.8 g (0.0050 mol); yield 57%. This mixture showed a nematic phase between 91 and 123°C:
• this mixture was dissolved in NMP (5 ml) and CuCN (0.46 g, 0.0051 mol) was added to the solution, followed by stirring to effect a reaction at 190 - 200°C for 11 hr.
• the reaction mixture was cooled and added to 30% aqueous ammonia.
• the reaction product was extracted with toluene.
• the extract was successively washed with 30% aqueous ammonia, water, dilute HCl, a saturated aqueous solution of sodium hydrogencarbonate, and a saturated aqueous solution of sodium chloride, and subsequently dried. By distilling off toluene from the dried extract, a crude reaction product was obtained in an amount of 1.5 g.
• This crude reaction product was purified by column chromatography on silica gel and further purified by recrystallization from ethanol so as to obtain a mixture (1.0 g, 0.003 mol) of two compounds having the structures shown below; yield 66%. This mixture showed a nematic phase between 61 and 177°C.
• Example 2 The procedures of Example 1 were repeated except that p-dibromobenzene was replaced by 2-fluoro-1,4-­dibromobenzene (57.2 g, 0.225 mol). As a result, compounds having the structures shown below were individually obtained:
• a compound of the formula (5.0 g, 0.024 mol) was dissolved in anhydrous diethyl ether (15ml), and lithium (0.33 g, 0.048 gram atom) was added to the solution, followed by stirring to effect a reaction under reflux for 4 hr. After completion of the reaction, the reaction mixture was cooled and an anhydrous diethyl ether solution (12 ml) of a compound (4.1 g, 0.022 mol) having the formula was added dropwise to the cooled reaction mixture at 10 - 15°C, followed by reaction at room temperature (25°C) for 30 min. After adding the reaction mixture to at 10 - 15°C, followed by reaction at room temperature (25°C) for 30 min.
• the extract was successively washed with dilute HCl, a saturated acidic aqueous solution of sodium sulfite, a saturated aqueous solution of sodium hydorgencarbonate and a saturated aqueous solution of sodium chloride, and subsequently dried. By distilling off the solvent, a crude reaction product was obtained. This crude reaction product was purified by column chromatography on silica gel and further purified by recrystallization from n-hexane to obtain a compound having the structure shown below in an amount of 3.7 g (0.011 mol):
• Example 3 The procedures of Example 3 were repeated except As a result, a mixture of two compounds having the structures shown below was obtained (yield 43%). This mixture showed a nematic phase between 160°C and 239°C.
• This crude reaction product was purified by column chromatography on silica gel and further purified by recrystallization from a mixed solvent of n-hexane and ethanol so as to obtain a mixture (4.2 g, 0.011 mol) of two compounds having the structures shown below; yield 50%.
• This mixture showed a nematic phase between 240 and 285°C.
• Example 5 The procedures of Example 5 were repeated except As a result, a mixture of two compounds having the structures shown below was obtained. This mixture showed a nematic phase between 148 and 236°C.
• the compound of formula (I) of the present invention has a nematic phase in the high temperature range and the lower limit of the temperature range for the appearance of a nematic phase is lower than in the case of known compounds having similar structures. Therefore, by mixing this compound with a nematic mixed liquid crystal which is commercially used today as a host liquid crystal, the N-I point of the mixed liquid crystal can be elevated and at the same time, the appearance of a crystalline or smectic phase in the mixed liquid crystal in the low temperature range can be prevented.

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• 1989
  • 1989-02-27 EP EP89103435A patent/EP0331091B1/de not_active Expired - Lifetime
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